Antoine Martin - Tourbillon Astronomique

Founded by master watchmaker Martin Braun and entrepreneur Antoine Meier, the manufacture Antoine Martin (the brand is the combination of the names of the two founders) is driven by innovation as a primary value.

Last year, Antoine Martin presented the fascinating Slow Runner, the first wristwatch in the world to operate at 7,200 beats per hour, or one hertz, an incredibly low frequency for the balance of a mechanical watch.

The year before, in 2012, Antoine Martin presented the Tourbillon Quantieme Perpétuel with its huge 14,1 mm tourbillon weighing just 0,62 grams. The same tourbillon is now combined with a host of astronomic complications in the Tourbillon Astronomique, a BaselWorld 2014 novelty.

On the front side of this new exclusive model, the large flying tourbillon positioned at 6 o'clock revolves around its own axis once a minute, while the escapement in the rotating cage ticks at 2.5 Hertz, or 18,000 beats per hour.

The two subdials at 2 and 4 o'clock display the times of sunrise and sunset respectively, adjusted to a location of the customer's choice. In order to establish the correct times for every customer, the control cams are individually produced on the basis of specific calculations before being integrated into the movement.

At 3 o'clock another sub-dial indicates the current season and sign of the zodiac. A version with a correct display of the seasons is available for customers who live in the southern hemisphere.

The date display at 1 o'clock is set using a correction button. To make the date more legible, Antoine Martin enlarged the sub-dial taking it into the edge of the glass.

The Equation of Time - between 11 and 12 o'clock - shows the difference between the real solar time and the mean or civil time. In fact, the length of a solar day actually varies daily as a consequence of the elliptical shape of the Earth’s orbit.

Due to space constraints, Antoine Martin opted for a retrograde moon phase display: a semi-transparent shadow gradually moves across the moon until new moon, then the disc changes direction and moves the other way until it reaches full moon. The moon disc, made of solid sterling silver, is very detailed. For an even more realistic look, the shadow-like disc is semi-transparent so that the contours and craters of the moon are still visible, as in the night sky.

Just below the brand logo, the day and night display shows the 24 hours of the day.

On the reverse side of the watch, we have the six-day power reserve indicator and the declination display which shows the latitude at which the sun at 12 noon stands 90° above the horizon and at which a stick standing upright in the ground would cast no shadow. The red line moves up and down between the Tropics of Cancer and Capricorn - i.e. between 23.5° northern latitude and -23.5° southern latitude - in the course of the year.

Finally, a plaque which is custom-made for each individual customer shows the geographic coordinates on the basis of which the sunrise and sunset times are calculated and adjusted.

The case of the Antoine Martin Tourbillon Astronomique (ref. TA01.710.1) is made of red gold and has a diameter of 39.5 mm. The price of this exclusive timepiece is CHF 500.000.